The guy that most people consider the best prospect left in the minors, Brown is also the guy that was famously off-limits in the Roy Halladay trade. When your organization won’t trade you, straight up, for the best pitcher in baseball (who is signing a three year, below market deal as part of the trade, no less), you’ve got quite a bit of value. There’s a pretty good chance that Brown could be a solid major league player tomorrow, and his physical size and abilities give him serious upside. Young power hitters who can also handle themselves on defense are pretty rare and highly coveted.

The former top prospect started to live up to his billing last year and has carried it over to 2010, establishing himself as a solid middle-of-the-rotation arm at age 24. He has good command of quality stuff, and while he’s a pretty extreme flyball guy, he makes it work by racking up a lot of strikeouts. That he’s been able to succeed in a park that’s about as poor a fit for his skillset as possible (all 11 of his home runs allowed this year have come at Yankee Stadium) is highly impressive. Considering that he’s under team control through 2013 at arbitration prices, he’s quite the bargain.

Romero has stumbled of late, but his emergence as one of the better young left-handed pitchers in the game couldn’t have come at a better time for the Jays. While he’ll never entirely replace Halladay, he’s doing a pretty decent impression for a 25-year-old in his second year in the big leagues. A groundball lefty with a plus change-up, Romero is able to miss enough bats to compensate for the fact that he doesn’t have great command. He’s not an ace, but considering he’ll make something close to the league minimum again next year before becoming arbitration eligible, he’s providing a lot of return on the Blue Jays investment.

The ultimate performance over tools guy in the big leagues right now, Prado’s success is a testament to how pedigree doesn’t mean everything. This is a guy who hit 15 home runs in 2,119 minor league plate appearances, and was simply not considered much of a prospect when he got to the big leagues. However, for the last three years, he’s been one of the best second baseman in baseball, adding some power to his already good contact rates and turning himself into a legitimate All-Star this season. He’s headed for his prime years as an already good player, and the Braves have him under control for three more seasons. He might be the most unexpected guy on this list, but he’s earned his spot here.

Latos wasn’t great last year as a rookie, but his second stint through the National League has been a lot more successful. The fastball command that was his hallmark in the minors has returned, and the slider is good enough to give him a strikeout pitch on most days. As a result, he’s having a terrific season as a 22-year-old, and while he’s benefiting from Petco and the National League, he fares well even after you adjust for those external effects. With five more years of team control, the Padres have to be thrilled with how quickly Latos has developed and just how much value they’ll be able to get from him before he heads to free agency.